Fluorosurfactants have many unique properties, and are useful as soil and water repellents, airplane hydraulic fluids, additives in firefighting foams, paints, coatings, clothing, carpets, leather, waxes, polishes, and the like. Fluorosurfactants like perfluorooctanoic acid (PFOA) are also used as surfactants in aqueous media for the polymerization of hydrophobic monomers, especially fluorinated monomers such as tetrafluoroethylene. See Erik Kissa, Fluorinated Surfactants and Repellents, Surfactant Science Series, Vol. 97, 2nd edition (2001) (“Kissa”). The most commonly used fluorosurfactants are perfluorooctanoic acid (PFOA, C7F15CO2H) and perfluorooctane sulfonate (PFOS, C8F17SO3X, X═K, Na, H).
Typically, fluorosurfactants are compounds having a hydrophobic (generally a perfluoroalkyl chain) and a hydrophilic moiety (generally carboxylate/sulfate/quaternary ammonium moiety, or the like). When the hydrophobic chain is a perfluoroalkyl group, such as the C7F15 or C8F17, groups of PFOA and PFOS, respectively, such compounds are highly resistant to biodegradation. However, the fluorosurfactants having such perfluoroalkyl hydrophobic chains are persistent, toxic, bioaccumulable, and accordingly are found in blood of many animals and humans all over the world. See, e.g., M. Houde et al., Environ. Sci. Tech. 40, (2006), 3463-3473; Boutevin, et al., J. Fluorine Chem. 134, (2012), 77-84. Accordingly, it is even possible that the United States Environmental Protection Agency (EPA) may eliminate the use of PFOA and PFOS in the near future owing to environmental concerns. There is thus a significant and urgent need in developing alternate fluorosurfactants that are biodegradable and environmentally friendly (see H. J. Lehmler, Chemosphere, 58, (2005), 1471-1496; G. Kostov et al., J. Fluorine Chem. 130, (2009), 1192-1199).